Adjuvant endocrine therapy (AET) is a crucial component of treatment used to prevent recurrence and reduce breast cancer-related mortality for breast cancer patients with hormone receptor positive disease. Studies report low rates of adherence to AET (38% to 86%) and in our preliminary work, 65% of breast cancer patients taking AET reported one or more non-adherent medication taking behaviors (e.g., skipped dose, forgot, adjusted dose) in the past month. Symptoms (e.g., arthralgia, vasomotor symptoms) associated with AET are strongly related to non-adherence and early discontinuation of treatment. Poor adherence to AET due to symptoms may compromise the effectiveness of AET. In the proposed randomized clinical trial, 400 women who are taking AET for breast cancer will be randomly assigned to one of two conditions: 1) a self- management intervention for improving adherence and symptom management, or 2) a general health education control condition. The self-management intervention integrates three key theory-based strategies for improving adherence to AET: coping skills training for managing symptoms (e.g., arthralgia, vasomotor symptoms), behavioral strategies for improving medication adherence, and symptom and medication education. The intervention addresses the specific symptoms a woman is experiencing and is designed to meet the needs of women who are at high risk for non-adherence to AET (e.g., low socioeconomic status, low literacy). The self-management intervention is administered by a nurse via the telephone, and combines the use of phone calls, an intervention workbook with audio-recorded materials, and tailored interactive voice messaging based on information exchanged during phone sessions and real-time adherence data obtained from wireless smart medication bottles. Women randomly assigned to the control condition will receive a general health education intervention that is delivered by a nurse via the telephone. This study will take place in the Duke Cancer Institute breast clinic and in community hospitals that are members of the Duke Cancer Network, which will allow access to women receiving care outside the medical center setting and increase generalizability of findings to a variety of settings. Adherence to AET will be assessed over the 18 month period following study enrollment using wireless smart medication bottles that provide real-time adherence data. Patient-reported outcome measures assessing symptoms, perceived necessity of AET, concerns about AET, and self-efficacy will be obtained at baseline and 3, 6, 12, and 18 months. To increase the likelihood of later implementation of the self-management intervention, the cost effectiveness of the intervention will be evaluated.